1. Field of the Invention
The present invention relates to apparatus and method of determining an optimal writing power for an aged writable disk after checking whether an inserted writable disk is aged or not.
2. Description of the Related Art
In general, an optimal writing power is dependent upon state or type of a recording medium, recording speed, and features of a disk device such as laser quality, laser type, writing strategy, temperature characteristic, and so on. Therefore, a disk device conducts an OPC (Optimal Power Calibration) using an indicative optimum writing power written on an inserted writable disk in order to determine an optimal writing power before recording data onto the writable disk.
In OPC, a disk device reads an indicative optimum writing power ‘Pind’ written on an inserted writable disk first. Then, it repeats writing 1-ATIP-long test data onto a PCA area of the disk 15 times as changing the power ‘Pind’ by a step (ΔP) every 1 ATIP advance. After completion of writing test data of 15 ATIP long, the disk device reads out the entire test data sequentially and determines an actual optimal writing power based on a characteristic curve made from the reproduced test data.
However, if a writable disk such as a CD-RW is aged, namely, if a writable disk has been repeatedly overwritten many times, an optimal writing power determined through an OPC may be not optimal to recording surface characteristic of an aged disk.
Therefore, it is necessary to exactly judge a disk to be aged or not and to conduct an improved optimal power determining manner being able to get more precise optimal writing power than a conventional OPC if the disk is aged.